Floor Deck

SMD’s metal floor decking products are commonly used as part of a composite floor slab, where the decking acts as both permanent formwork and tensile reinforcement (sagging) in the bottom of the slab (basis of design in accordance with BS5950: Parts 4 & 6 or Eurocodes 3 and 4).

Alternatively, our decking profiles may be used as permanent formwork only. In this situation any reinforcement required to support the specified imposed loads is to be designed by the project structural engineer, ignoring any contribution from the metal decking.

All our profiles use steel strip in compliance with BS EN 10143 & BS EN 10346 with guaranteed minimum yield strengths of 350 and 450 N/mm² and a minimum coating mass of 275g/m².

All SMD decks are manufactured from galvanised steel coil to BS EN 10346 with a standard 275g/m² coating which equates to 0.02mm (20μm) per face. Although the galvanising provides a protective coating, it does weather, albeit at approximately one tenth of the rate of bare steel (depending upon the prevailing conditions).

Useful references on the life to first maintenance (LTFM) of galvanised steel coil include:

• Galvanizers Association, “The Engineers and Architects Guide: Hot-dip Galvanizing”
• Corus Strip Products UK, “Protected with strength – Solutions in Galvatite hot-dip galvanised steel”
• The Steel Construction Institute, P262 – Durability of Light Steel Framing in Residential Building: Second Edition
• SCI Advisory Desk Note 247: Use of Composite Construction in an Aggressive Environment,” New Steel Construction, April 2010.

In summary, the above references conclude the LTFM for galvanised steel coil with a 20 μm coating as shown in Table 7.4a for the different corrosivity categories.